The present invention relates to a female component for a mechanical refastenable fastening device. More particularly, this invention relates to a low-cost is multi-layer female component for such a fastening device, and a method for producing such a component.
Refastenable fastening devices of the hook and loop-type are currently used widely in a great number of situations. Such refastenable fastening devices have been used in clothing, disposable articles, and various miscellaneous articles such as safety belts and the like. Such devices are used when it is desirable to create a refastenable bond between two or more articles or between several surfaces of the same article. In certain applications, these refastenable fastening devices have replaced conventional buckles, zippers, buttons, snaps, tie fasteners, and sewing.
A popular type of mechanical fastener currently in wide use which utilizes mechanical entanglement to create a refastenable bond is sold under the trademark xe2x80x9cVELCROxe2x80x9d. VELCRO fastening devices are described in greater detail in U.S. Pat. No. 2,717,437, U.S. Pat. No. 3,009,235, U.S. Pat. No. 3,266,113, U.S. Pat. No. 3,550,837, U.S. Pat. No. 4,169,303, and U.S. Pat. No. 4,984,339.
VELCRO fasteners utilize two components, a male component and a female component. The male and female components are often referred to as the hook and loop components, respectively. The hook component consists of a fabric which contains a plurality of resilient, upstanding hook-shaped elements. The female component of the fastening device consists of a fabric containing a plurality of upstanding loops on its surface. When the hook component and the loop component are pressed together in a face-to-face relationship to close the fastening device, the hooks entangle the loops forming a plurality of mechanical bonds between the individual hooks and loops. When these bonds have been created, the components will not generally disengage under normal conditions. This is because it is very difficult to separate the components by attempting to disengage all of the hooks at once. However, when a gradual peeling force is applied to the components, disengagement can be easily effected. Under a peeling force, since the hooks are comprised of a resilient material, they will readily open to release the loops.
This type of fastening device has been found especially useful on disposable articles such as disposable garments, disposable diapers, disposable packages, cartons and the like. Such fastening devices provide a secure closing means. However, the use of existing fastening devices of this type on disposable articles has been limited due to the fact that such fastening devices are relatively costly. The major reason that such fastening devices are costly is that they have high manufacturing costs. These high manufacturing costs are associated with both the hook and loop components of these devices.
Conventional hook and loop components are typically formed by making a fabric with a number of woven loops extending outwardly from a backing. The loops may be provided by weaving a base fabric containing supplementary threads to form the loops, or by knitting loops into a fabric. In other hook and loop components, the loops may be formed by pleating or corrugating processes. The hook components of such fastening devices are typically formed by subsequently cutting the loops. The cut loops serve as the hooks of the hook component.
These processes generally produce costly hook and loop fastening materials because they are relatively slow. The hook and loop components of such fastening devices are also usually made out of the same relatively expensive material. This material is generally relatively expensive for the hook component because the material used in the hook component needs to be resilient so that the hooks can disengage from the loop component when the device is opened. Conventional loop fastening materials are generally made entirely out of a single material. This material is generally relatively expensive due to the need of such material to be strong enough to hold the engaged hooks when subjected to forces applied on the fastening device.
Several attempts have been made to make alternative types of female components for fastening devices. However, such attempts have generally suffered from a number of drawbacks.
One such attempt is described in U.S. Pat. No. 3,708,833 issued to Ribich, et al. on Jan. 9, 1973. The Ribich, et al. patent discloses a refastenable fastening device having a female component that comprises reticulated urethane foam secured to a backing layer. The female component disclosed in the Ribich, et al. patent suffers from the drawback that foams typically do not have enough openings for the hooks of conventional hook components to penetrate. Reticulated foam does not have sufficient strength to hold such hooks when forces are applied to the fasting device. Further manufacturing reticulated foam is a relatively expensive process.
U.S. Pat. No. 3,905,071 issued to Brumilk on Sep. 16, 1975 discloses a xe2x80x9cpress-through self-gripping device.xe2x80x9d The device described in the Brumlik patent does not appear to be suitable for use in a refastenable fastening device that utilizes a conventional mating hook component with resilient hooks. The fastening device disclosed in the Brumlik patent is intended to be used for fastening one or more sheets of material between a gripping member and a receiving member. The gripping member disclosed in the Brumlik patent has rigid and stiff needle-shaped elements for gripping elements. These needle-like elements are particularly unsuitable for use in fastening devices on disposable absorbent articles. The disclosure of the Brumlik patent, thus, appears to be limited to devices that employ gripping elements adapted to penetrate and pass through several sheets of material and lodge inside a receiving member.
Therefore, there is a need for a low-cost fastening device for disposable articles. In particular, there is a need for such low-cost fastening devices to perform in a manner comparable to the more expensive commercially-available fastening devices.
It is an object of the present invention to provide an improved low-cost female component for a fastening device.
It is another object of the present invention to provide a female component for a fastening device that can be used with both commercially-available hook components having resilient individual hooks, as well as less expensive hook components with more brittle hooks than those currently in use.
It is a further object of the present invention to provide a low-cost female component that makes more efficient use of materials than existing fastening devices and that utilizes reduced amounts of expensive materials.
It is still another object of the present invention to form a low-cost female component for a refastenable fastening device by stacking materials on top of one another which have certain desired individual characteristics for entangling and engaging the hooks of a mating hook component.
It is a still further object of the present invention to provide a low-cost and improved method for producing such a female component.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in connection with the accompanying drawings.
The present invention provides a multi-layer (or multi-zone) female component or engaging a complementary hook component in a refastenable fastening device. The female component of the present invention is capable of engaging a hook component that has individual hook elements having blunt heads. The female component does not require individual loops of the conventional type to be present. Typically, the hooks will be engaged by elements that present the female component with a relatively flat outwardly-facing surface.
The female component comprises at least two, and preferably three layers or zones. Each zone has certain of the desired individual characteristics for entangling and holding the hooks of the mating hook component. The zones include a first zone (the xe2x80x9centanglementxe2x80x9d zone), a second zone (the xe2x80x9cspacingxe2x80x9d zone), and a backing. The entanglement zone may be a woven fabric, a nonwoven web, or some other type of material that has fibers, strands, or the like to entangle the hooks of the hook component. There should be sufficient space between these fibers to admit the hooks of the hook component. The spacing zone may be any suitable material that provides space for the hooks to occupy after they have been admitted by the entanglement zone. The spacing zone may be comprised of the same type of material as the entanglement zone, or a completely different material. For instance, in one alternative embodiment, the spacing zone can comprise loose particles. The spacing zone will preferably be a xe2x80x9chigh loftxe2x80x9d (high caliper) material so that it will be able to provide adequate space for the stems and heads of the hooks. The backing is adjacent to the spacing zone. The backing provides a foundation for the entanglement and spacing zones.
In one preferred embodiment, the entanglement zone comprises a first nonwoven web having a basis weight of between about 7 and about 15 g/yd2 (about 8.5 to about 18 g/meter2) and fibers with a denier of between about 2 and about 6; the spacing zone comprises a second nonwoven web having a basis weight of between about 7 and about 30 g/yd2 (about 8.5 to about 36 g/meter2) and fibers with a denier of between about 6 and about 15; and the entanglement and spacing zones are held in place relative to a film backing with the spacing zone in between the entanglement zone and the backing.
This arrangement of layers results in a lower cost female component. Less expensive materials can be used in the spacing zone, in lieu of using the same, relatively expensive raw material for the entire composition of the female component. The female component can also be produced by a lower cost laminating process, rather than the conventional weaving, knitting, pleating, or corrugating processes.
The preferred embodiment of the female component described above is formed by a method comprising the steps of:
(a) providing a first material having a basis weight of between about 7 and about 15 g/yd2 (about 8.5 to about 18 g/meter2) and being comprised of fibers with a denier of between about 2 and about 6 for a first zone;
(b) providing a second material having a basis weight of between about 7 and about 30 g/yd2 (about 8.5 to about 36 g/meter2) and being comprised of fibers with a denier of between about 6 and about 15 for a second zone;
(c) providing a backing material; and
(d) securing at least the first material to the backing material so that the second material is positioned between the first material and the backing material.
The present invention also relates to a fastening device having a hook fastening component and a female component. The female component comprises the multi-layer female component of the present invention. The hook fastening component comprises a hook fastening component which had a base and a number of individual hooks extending from the base. The multi-layer female component and the complementary hook fastening component provide a secure refastenable closing means that will resist forces encountered during use.
The present invention also relates to disposable articles and more particularly to a disposable diaper having such an improved fastening device.